Github user markap14 commented on the issue:
https://github.com/apache/nifi/pull/2770
For those reviewing, the simplest way to verify the fix is to create a
DebugFlow processor. Set the "CustomValidate Pause Time" property to "70
millis" and when you apply the update, you should see the component is
validating (it's possible that validation will complete before the 50 ms
timeout due to java timing precision - if this happens, just configure
processor and click "Apply" again). Change the duration to 25 millis and you
should no longer see the validation occurring. Of course, because of timing
issues you may see some variance.
---
